Projected studies include: (1) Characterization of the purified proline hydroxylase from earthworm subcuticular epithelium; (2) Excretion of total and free 3-hydroxyproline in human urine; (3) Peptide distribution of urinary 3-hydroxyproline; (4) Hydroxylation of proline residues in basement membrane collagen; (5) Metabolic degradation of 3-hydroxyproline in mammals; (6) Synthesis and properties of collagen-like polypeptides containing proline, 4-hydroxyproline or 3-hydroxyproline. BIBLIOGRAPHIC REFERENCES: Gryder, R. M., Lamon, M., and Adams, E. Sequence Position of 3-Hydroxyproline in Basement Membrane Collagen. J. Biol. Chem. 250, 2470 (1975). Heacock, A. M., and Adams, E. Formation and Excretion of Pyrrole-2-carboxylic Acid: Whole Animal and Enzyme Studies in the Rat. J. Biol. Chem. 250, 2599 (1975).